(1-y+x分之y)÷y2-x2分之x

问题描述:

(1-y+x分之y)÷y2-x2分之x

=[(x+y)-y]/(x+y)÷[-x/(x+y)(x-y)]
=x/(x+y)×[-(x+y)(x-y)]/x
=-(x-y)
=y-xлл����